According to Desert USA, sexually mature rhino adults mate between seven and 10 years. Calves are born 16 to 18 months later, nurse for about a year and live with the mother for another three years. The youngsters then strike out on their own. Males stake out a territory, but females share their areas with other females and calves.
According to Bio Expedition, rhinos are generally solitary animals, but sometimes travel in groups of up to 15. Scientists believe plentiful food supplies and safety from predators are major reasons for this unusual behavior. The International Rhino Foundation states that the animals have few natural predators, although leopards, lions, hyenas, wild dogs and crocodiles do occasionally kill a calf. Man is the number one enemy of the rhinoceros.
Although females are less territorial than males, both are merciless fighters. According to the Honolulu Zoo, "up to half of the males and one third of the females die from interspecies fight wounds." Despite a threatening horn on their snouts, rhinoceros use incisors and canine teeth to slash and gouge their opponents.
The African Wildlife Foundation states that rhino populations have declined 90 percent over the past 40 years. The lifespan of a wild rhinoceros is approximately 35 years, but in captivity it often lives up to 40 years.